On Thursday night, the Red Sox clinched their first playoff spot since 2009, and did so with John Lackey on the mound, delivering a brilliant two-hit, complete-game effort.

On Friday night, the Sox have a chance to check another box and win their first division title since 2007. If they succeed, it's likely that Jon Lester, Friday's starter, will be the winning pitcher.

Talk about symbolism. Talk about fitting.

Lackey is emblematic of the team's turnaround, which is why it was perfect for him to be the pitcher of record when the team qualified for the post-season for the first time in four seasons.

Two years ago, Lackey was viewed -- fairly or unfairly -- as the face of an entitled group of players: churlish at times, and frankly, juvenile, having taken part in the chicken-and-beer hijinks that came to represent the team's September downfall.

When it was announced after the 2011 season that Lackey would be undergoing Tommy John surgery, it was seen largely as addition by subtraction. After all, how would the Red Sox miss a starting pitcher who racked up a 6.41 ERA, the highest among American League qualifiers?

Of course, what wasn't known at the time was that Lackey was pitching with a torn ligament in his elbow, but with the team having few other options, Lackey continued to take the ball in the final weeks of the season.

When Lackey returned this spring, he was almost unrecognizable. Though team sources maintained that Lackey had dropped 30 pounds during his rehab from elbow surgery, it looked like a far greater amount. His body was lean rather than thick, his face drawn rather than jowly.

In spring training, it was obvious that the year away from the game had had an impact on Lackey. He was happy to be taking part in even the most mundane spring training tasks and energized by the chance to compete again.

In media sessions, once contentious and full of head-shakes and eye rolls, were engaging and spirited.

And once the season started -- following a brief forearm scare in his first start back, sidelining him for a few weeks -- the real metamorphosis began. This, finally, was the Lackey the Red Sox thought they were getting when they signed him to a five-year deal after the 2009 season.

Throughout the season, Lackey allowed three runs or fewer in 21 of his 28 starts. He routinely went deep into games, especially as he built arm strength over the course of the season: in 15 of his last 17 starts, he retired at least one batter in the seventh inning.

Thursday, in the playoff clincher, he flirted with a no-hitter, holding the Orioles hitless into the seventh before Adam Jones ended that bid and the shutout with a towering homer to left.

Lackey insisted that the loss of the no-hitter wasn't an issue, that the Sox were focused on a team goal. And you believed him.

If Lackey stood as a living example of the team's redemption, than Friday's starter, Jon Lester, represents the team's turnaround on the field, the circle complete.

As far back as spring training, manager John Farrell identified Lester as the team's key performer. Sure, David Ortiz was needed to anchor the middle of the lineup and Jacoby Ellsbury would have to serve as the table-setter and others were critical to a winning effort.

But Lester was the team's top starter, coming off the worst season in his career. Lackey was unknown, given his surgery and a missed year. Ryan Dempster would be making the transition to the American League for a full season and his output was uncertain.

Even Clay Buchholz, who was the team's best pitcher when healthy, didn't have the same significance attached to his performance.

If the Red Sox were going to go somewhere in 2013, it would be Lester who guided them there.

And so it was. Lester began the season by outdueling CC Sabathia at Yankee Stadium and ran his record to 6-0 by mid-May. More than anyone else, he was behind the team's strong start.

When he began to falter in late May and June, the Red Sox never looked more vulnerable. If they couldn't count on Lester, the thinking went, they had no one else to fall back on.

Lester demonstrated poor body language on the mound during this skid, and his cut fastball, so essential to his success, began to fail him.

But given an 11-day respite between starts at the All-Star break, Lester returned re-invigorated. Since the All-Star break, as the Red Sox have navigated injuries and stretched their lead in the American League East, Lester posted a 2.33 ERA in the second half.

In eight of his final 10 starts, he allowed two runs or fewer, and as the Red Sox unofficially dispatched the Yankees over the weekend at Fenway, the game featured Lester topping 200 innings for the season, while once more besting Sabathia.

It was if the season had come full circle.

Friday night offers the possibility of closure. The same lefty who is the last Red Sox pitcher to win a World Series game has a chance to win a game in which they claim a division title for the first time since that same 2007 championship season.

Funny how these things work.

Funny and fitting.

Sean McAdam serves as Comcast SportsNet's MLB Insider. Read more from Sean here, or follow him on Twitter or Facebook.